Truedyne VLO-M2 Sensor for liquids

The VLO-M2 viscosity sensor measures the viscosity of a fluid in a microelectromechanical system (MEMS system). The medium is guided in the sensor via a pressure gradient to the omega chip, an omega-shaped microchannel. This vibronic measuring system generates the measured values by setting a silicon tube in the chip into resonant vibration and analysing this. This is because the vibration quality depends on the viscosity of the liquid in the microchannel. At the same time – and independent of the viscosity – the density of the medium can be determined via the frequency of the microchannel. Since temperature influences both viscosity and density, the temperature of the medium is also recorded in real time in the chip. In this way, the temperature effect can be compensated.

Thanks to the measurement in the MEMS system, the sensor is only 30 x 80 x 15 mm in size and can be accommodated even in tight spaces. The high-precision measurement results are immediately available, allowing continuous measurement during the process. The density of liquids depends on their temperature. To compensate for this effect, an integrated platinum resistor detects the temperature of the liquid.

The viscosity sensor sends the measured data to the readout system via the data line in Modbus RTU transmission mode.